CN103592645A - Velocity ambiguity solution method of pseudo-random code phase-modulation continuous wave radar - Google Patents

Abstract

The invention discloses a velocity ambiguity solution method of a pseudo-random code phase-modulation continuous wave radar, and relates to the field of continuous wave radars. The velocity ambiguity solution method of the pseudo-random code phase-modulation continuous wave radar is used for measuring the target velocity, and is a design method with the unambiguous distance and the ambiguous velocity. Phase modulation is carried out on carrier waves through staggered pseudo-random codes, the pseudo-random codes are alternately used, velocity ambiguity solution is carried out by using target velocity remainders obtained through twice measurement, and thus the real velocity of a target can be determined. Due to the fact that the velocity ambiguity solution method ensures that distance measurement within the radar measuring range is unambiguous, the capacity of the radar for detecting the target in the distance can be improved through distance subsection target detection, the frequency of false alarms caused by nearby ground clutter and nearby sea clutter can be reduced through a distance-and-sensitivity control method, and the capacity of the radar for detecting low-speed targets in a complex environment is improved.

Description

The fuzzy calculation method of a kind of pseudo-random code phase modulating continuous wave radar speed

Technical field

The present invention relates to a kind of method for solving target speed in continuous wave pseudo-random code modulation field of radar, be specially adapted to the velocity survey of miniaturization pseudo-random code modulated continuous wave radar.

Background technology

At present, in pseudo-random code modulated continuous wave radar, adopt Doppler's target detection system at home and abroad, there is no velocity ambiguity, but range ambiguity is serious, its advantage is in the higher Shi Wu clutter district, detection zone of Doppler, detects superior performance, but Doppler compared with the detection zone at the end, clutter, target are often aliasing in together after Range-based, are difficult to distinguish.

Summary of the invention

To be solved by this invention be exactly in radar range ability distance not fuzzy, and the problem of velocity ambiguity, adopt irregular pseudo-random code to carry out phase-modulation to carrier wave, and alternate wheel method, utilize the target velocity remainder measuring for twice to carry out velocity ambiguity and resolve, thereby can determine the true velocity of target.The method has guaranteed that range observation is unambiguous in radar range ability, thereby can improve the detectivity of radar to distant object by detecting apart from segmented objects, can be by the false-alarm that distance-sensitivity control method reduces because of nearby, extra large clutter causes, raising radar in complex environment to the detectability of target at a slow speed.

For solving problem set forth above, the present invention proposes the fuzzy calculation method of a kind of pseudo-random code phase modulating continuous wave radar speed, comprise the following steps:

(1) radar adopts a, pseudo-random code that two groups of clock frequencies of b are different in wave beam residence time, to complete an alternate wheel to send out;

(2) the radar electromagnetic wave signal that receiving target reflects respectively, and therefrom extract target component, target component comprises: distance, orientation, speed remainder and measurement are constantly;

(3) judgement of same target: if the distance of target, orientation and measurement meet data correlation condition constantly, be same target;

Step (3) specifically comprises following three steps:

301, time correlation judgement: if meet time correlation condition, proceed the correlated judgment of next step;

Time correlation condition is: T ₁-T ₂≤ Δ t;

Wherein: Δ t is the target measurement cycle;

T ₁for the target measurement moment of a group pseudo-random code in measuring period;

T ₂for the target measurement moment of b group pseudo-random code in measuring period;

302, orientation correlated judgment: if meet orientation correlated condition, proceed the correlated judgment of next step;

First calculate orientation thresholding:

Orientation thresholding: $G_A=\frac{\mathrm{\Δt}{v}_{\max }}{r_{\mathrm{pk}}}+k_A+{\mathrm{\σ}}_A;$

V wherein _maxfor target travel maximal rate, Δ t is the target measurement cycle, σ _afor orientation angles error, k _abe respectively orientation thresholding coefficient;

Orientation correlated condition is: | A ₁-A ₂|≤G _a

In formula: A ₁for the target side place value of a group pseudo-random code in measuring period;

A ₂for the target side place value of b group pseudo-random code in measuring period;

303, Range-based judgement: if meet Range-based condition, think same target;

Range-based condition:

|R ₁-R ₂|≤Δtv _max+k _Rσ _R

In formula: v _maxfor target travel maximal rate, Δ t is the target measurement cycle, k _rfor distance threshold coefficient, σ _rfor distance error, R ₁for the target range value of a group pseudo-random code in measuring period, R ₂for the target range value of b group pseudo-random code in measuring period.

(4) target component to same target, gets respectively a, and the speed remainder of two groups of pseudo-random codes of b and the fuzzy speed mould of integral multiple value are added, and obtains a, each self-corresponding target possible speed value of two groups of pseudo-random codes of b:

${\hat{V}}_{\mathrm{ai}}=i\×V_{\mathrm{mod}a}+V_1;$

${\hat{V}}_{\mathrm{bj}}=j\×V_{\mathrm{mod}b}+V_2;$

In formula: i, j=0,1 ..., N, i, j, N are natural number;

V ₁the speed remainder measuring during for transmitting a group pseudo-random code;

V ₂the speed remainder measuring during for transmitting b group pseudo-random code;

V _modafuzzy speed mould value for the covering of a group pseudo-random code;

V _modbfuzzy speed mould value for the covering of b group pseudo-random code;

for the target possible speed value of utilizing a group pseudo-random code to calculate;

for the target possible speed value of utilizing b group pseudo-random code to calculate;

(5) to target possible speed value corresponding to a group pseudo-random code with target possible speed value corresponding to b group pseudo-random code

get difference:

$\mathrm{\Δ}{d}_{\mathrm{ij}}=|{\hat{V}}_{\mathrm{ai}}-{\hat{V}}_{\mathrm{bj}}|;i,j=\mathrm{0,1},......,N;$

As difference DELTA d _ij≤ 3 σ _v, σ wherein _vfor data noise, meet velocity error compression context, corresponding i, j is the fuzzy mould value of true velocity corresponding to target velocity, is designated as m, n, target velocity just can be expressed as:

V=m * V _moda+ V ₁or V=n * V _modb+ V ₂;

In formula: V is target velocity;

M is target true velocity Fuzzy Number Valued corresponding to a group pseudo-random code;

N is target true velocity Fuzzy Number Valued corresponding to b group pseudo-random code;

Completing target velocity resolves.

The present invention compares with background technology, has the following advantages:

1. adopt apart from segmented objects detection method, closely clutter can not disturb the detection of distant object, and distant object detectability strengthens;

2. can be by the false-alarm that distance-sensitivity control method reduces because of nearby, extra large clutter causes, raising radar in complex environment to the detectability of target at a slow speed.

Embodiment

The fuzzy calculation method of phase modulating continuous wave radar speed, modulates the repetition frequency of pseudo-code by choose reasonable, make in radar range ability distance not fuzzy, and speed is fuzzy, specifically comprises the following steps:

(1) radar adopts a, pseudo-random code that two groups of clock frequencies of b are different in wave beam residence time, to complete an alternate wheel to send out;

In embodiment, radar range is 25km, and radar wavelength is 0.03m, and pseudo-random code a clock frequency is elected 2.5MHz as, and pseudo-random code b clock frequency is elected 3MHz as, and pseudo-random code code length is elected 511 as, and corresponding unambiguous distance is: 25.5km; What pseudo-random code a was corresponding is 73.39m/s without fuzzy speed, and what pseudo-random code b was corresponding is 88.06m/s without fuzzy speed; Pseudo-random code a, b alternate wheel are sent out, and it is 20ms that wheel is sent out the time interval;

(2) the radar electromagnetic wave signal that receiving target reflects respectively, and therefrom extract target component, target component comprises: distance, orientation, speed remainder and Measuring Time;

(3) judgement of same target: if the distance of target, orientation and measurement meet data correlation condition constantly, be same target;

Step (3) specifically comprises following three steps:

301, time correlation judgement: if meet time correlation condition, proceed the correlated judgment of next step;

Time correlation condition is: T ₁-T ₂≤ Δ t;

Wherein: Δ t is the target measurement cycle;

T ₁for the target measurement moment of a group pseudo-random code in measuring period;

T ₂for the target measurement moment of b group pseudo-random code in measuring period;

302, orientation correlated judgment: if meet orientation correlated condition, proceed the correlated judgment of next step;

First calculate orientation thresholding:

Orientation thresholding: $G_A=\frac{\mathrm{\Δt}{v}_{\max }}{r_{\mathrm{pk}}}+k_A+{\mathrm{\σ}}_A;$

V wherein _maxfor target travel maximal rate, Δ t is the target measurement cycle, σ _afor orientation angles error, k _abe respectively orientation thresholding coefficient;

Orientation correlated condition is: | A ₁-A ₂|≤G _a

In formula: A ₁for the target side place value of a group pseudo-random code in measuring period;

A ₂for the target side place value of b group pseudo-random code in measuring period;

303, Range-based judgement: if meet Range-based condition, think same target;

Range-based condition:

|R ₁-R ₂|≤Δtv _max+k _Rσ _R

In formula: v _maxfor target travel maximal rate, Δ t is the target measurement cycle, k _rfor distance threshold coefficient, σ _rfor distance error, R ₁for the target range value of a group pseudo-random code in measuring period, R ₂for the target range value of b group pseudo-random code in measuring period.

In embodiment, the echo target component of a code section launch time is R ₁=9350m, A ₁=35.6 °, V ₁=60m/s, T ₁=10.06s; The echo target component of b code section launch time is R ₂=9330m, A ₂=35.6 °, V ₂=3m/s, T ₂=10.08s; By calculating measured distance, orientation, time parameter, meet data correlation relation, can think same target;

(4) target component to same target, gets respectively a, and the speed remainder of two groups of pseudo-random codes of b and the fuzzy speed mould of integral multiple value are added, and obtains a, each self-corresponding target possible speed value of two groups of pseudo-random codes of b:

${\hat{V}}_{\mathrm{ai}}=i\×V_{\mathrm{mod}a}+V_1;$

${\hat{V}}_{\mathrm{bj}}=j\×V_{\mathrm{mod}b}+V_2;$

In formula: i, j=0,1 ..., N, i, j, N are natural number;

V ₁the speed remainder measuring during for transmitting a group pseudo-random code;

V ₂the speed remainder measuring during for transmitting b group pseudo-random code;

V _modafuzzy speed mould value for the covering of a group pseudo-random code;

V _modbfuzzy speed mould value for the covering of b group pseudo-random code;

for the target possible speed value of utilizing a group pseudo-random code to calculate;

for the target possible speed value of utilizing b group pseudo-random code to calculate;

In embodiment, calculate

${\hat{V}}_{a0}=0\×V_{\mathrm{mod}a}+V_1=0\×73.39+60=60m/s$

${\hat{V}}_{a1}=1\×V_{\mathrm{mod}a}+V_1=1\×73.39+60=133.39m/s$

${\hat{V}}_{a2}=2\×V_{\mathrm{mod}a}+V_1=2\×73.39+60=206.78m/s$

${\hat{V}}_{a3}=3\×V_{\mathrm{mod}a}+V_1=3\×73.39+60=280.17m/s$

${\hat{V}}_{a4}=4\×V_{\mathrm{mod}a}+V_1=4\×73.39+60=353.56m/s$

${\hat{V}}_{a5}=5\×V_{\mathrm{mod}a}+V_1=5\×73.39+60=426.95m/s$

${\hat{V}}_{a6}=6\×V_{\mathrm{mod}a}+V_1=6\×73.39+60=500.34m/s$

Calculate

${\hat{V}}_{b0}=0\×V_{\mathrm{mod}b}+V_2=0\×88.06+3=3m/s$

${\hat{V}}_{b1}=1\×V_{\mathrm{mod}b}+V_2=1\×88.06+3=91.06m/s$

${\hat{V}}_{b2}=2\×V_{\mathrm{mod}b}+V_2=2\×88.06+3=179.12m/s$

${\hat{V}}_{b3}=3\×V_{\mathrm{mod}b}+V_2=3\×88.06+3=267.18m/s$

${\hat{V}}_{b4}=4\×V_{\mathrm{mod}b}+V_2=4\×88.06+3=355.24m/s$

${\hat{V}}_{b5}=5\×V_{\mathrm{mod}b}+V_2=5\×88.06+3=443.3m/s$

${\hat{V}}_{b6}=6\×V_{\mathrm{mod}b}+V_2=6\×88.06+3=531.36m/s$

(5) to target possible speed value corresponding to a group pseudo-random code

with target possible speed value corresponding to b group pseudo-random code

get difference:

$\mathrm{\Δ}{d}_{\mathrm{ij}}=|{\hat{V}}_{\mathrm{ai}}-{\hat{V}}_{\mathrm{bj}}|;i,j=\mathrm{0,1},......,N;$

As difference DELTA d _ij≤ 3 σ _v, σ wherein _vfor data noise, meet velocity error compression context, corresponding i, j is the fuzzy mould value of true velocity corresponding to target velocity, is designated as m, n, target velocity just can be expressed as:

V=m * V _moda+ V ₁or V=n * V _modb+ V ₂;

In formula: V is target velocity;

M is target true velocity Fuzzy Number Valued corresponding to a group pseudo-random code;

N is target true velocity Fuzzy Number Valued corresponding to b group pseudo-random code;

Completing target velocity resolves.

In embodiment, calculate Δ d _ij, be expressed as matrix form as follows:

$\mathrm{\Δd}=\left|\begin{array}{ccccccc}57& -31.06& -119.12& -207.18& -295.24& -383.3& -471.36\\ 130.39& 42.33& -45.73& -133.79& -221.85& -309.91& -397.97\\ 203.78& 115.72& 27.66& -60.4& -148.46& -236.52& -324.58\\ 277.17& 189.11& 101.05& 12.99& -75.07& -163.13& -251.19\\ 350.56& 262.5& 174.44& 86.38& -1.68& -89.74& -177.8\\ 423.95& 335.89& 247.83& 159.77& 71.71& -16.35& -104.41\\ 497.34& 409.28& 321.22& 233.16& 145.1& 57.04& -31.02\end{array}\right|$

If radar measurement errors σ _v=2m/s, Δ d satisfies condition _ij≤ 3 σ _vonly have:

Δd _ij＝-1.68（i=4，j=4）

So have: m=4, n=4.

Target velocity can be calculated as follows:

$\begin{array}{c}V=\frac{1}{2}[(m\×V_{\mathrm{mod}a}+V_1)+(n\×V_{\mathrm{mod}b}+V_2)]\\ =\frac{1}{2}[(4\×73.39+60)+(4\×88.06+3)]=354.4m/s\end{array}$

Completing target velocity resolves.

Claims (2)

1. the fuzzy calculation method of pseudo-random code phase modulating continuous wave radar speed, comprises the following steps:

(1) radar adopts a, pseudo-random code that two groups of clock frequencies of b are different in wave beam residence time, to complete an alternate wheel to send out;

(2) the radar electromagnetic wave signal that receiving target reflects respectively, and therefrom extract target component, target component comprises: distance, orientation, speed remainder and measurement are constantly;

(3) judgement of same target: if the distance of target, orientation and measurement meet data correlation condition constantly, be same target;

(4) target component to same target, gets respectively a, and the speed remainder of two groups of pseudo-random codes of b and the fuzzy speed mould of integral multiple value are added, and obtains a, each self-corresponding target possible speed value of two groups of pseudo-random codes of b:

${\hat{V}}_{\mathrm{ai}}=i\×V_{\mathrm{mod}a}+V_1;$

${\hat{V}}_{\mathrm{bj}}=j\×V_{\mathrm{mod}b}+V_2;$

In formula: i, j=0,1 ..., N, i, j, N are natural number;

V ₁the speed remainder measuring during for transmitting a group pseudo-random code;

V ₂the speed remainder measuring during for transmitting b group pseudo-random code;

V _modafuzzy speed mould value for the covering of a group pseudo-random code;

V _modbfuzzy speed mould value for the covering of b group pseudo-random code;

for the target possible speed value of utilizing a group pseudo-random code to calculate;

for the target possible speed value of utilizing b group pseudo-random code to calculate;

(5) to target possible speed value corresponding to a group pseudo-random code

with target possible speed value corresponding to b group pseudo-random code

get difference:

$\mathrm{\Δ}{d}_{\mathrm{ij}}=|{\hat{V}}_{\mathrm{ai}}-{\hat{V}}_{\mathrm{bj}}|;i,j=\mathrm{0,1},......,N;$

As difference DELTA d _ij≤ 3 σ _v, σ wherein _vfor data noise, meet velocity error compression context, corresponding i, j is the fuzzy mould value of true velocity corresponding to target velocity, is designated as m, n, target velocity just can be expressed as:

V=m * V _moda+ V ₁or V=n * V _modb+ V ₂;

In formula: V is target velocity;

M is target true velocity Fuzzy Number Valued corresponding to a group pseudo-random code;

N is target true velocity Fuzzy Number Valued corresponding to b group pseudo-random code;

Completing target velocity resolves.

2. the fuzzy calculation method of a kind of pseudo-random code phase modulating continuous wave radar speed according to claim 1, is characterized in that: step (3) specifically comprises following three steps:

301, time correlation judgement: if meet time correlation condition, proceed the correlated judgment of next step;

Time correlation condition is: T ₁-T ₂≤ Δ t;

Wherein: Δ t is the target measurement cycle;

T ₁for the target measurement moment of a group pseudo-random code in measuring period;

T ₂for the target measurement moment of b group pseudo-random code in measuring period;

302, orientation correlated judgment: if meet orientation correlated condition, proceed the correlated judgment of next step;

First calculate orientation thresholding:

Orientation thresholding: $G_A=\frac{\mathrm{\Δt}{v}_{\max }}{r_{\mathrm{pk}}}+k_A+{\mathrm{\σ}}_A;$

V wherein _maxfor target travel maximal rate, Δ t is the target measurement cycle, σ _afor orientation angles error, k _abe respectively orientation thresholding coefficient;

Orientation correlated condition is: | A ₁-A ₂|≤G _a

In formula: A ₁for the target side place value of a group pseudo-random code in measuring period;

A ₂for the target side place value of b group pseudo-random code in measuring period;

303, Range-based judgement: if meet Range-based condition, think same target;

Range-based condition:

|R ₁-R ₂|≤Δtv _max+k _Rσ _R

In formula: v _maxfor target travel maximal rate, Δ t is the target measurement cycle, k _rfor distance threshold coefficient, σ _rfor distance error, R ₁for the target range value of a group pseudo-random code in measuring period, R ₂for the target range value of b group pseudo-random code in measuring period.